244 The American Geologist. October, 1896 
croscope did not aiipeiir to be very sharp, but wa? marked b}' 
a line of biotite shreds and a finer grained structure in the 
pegmatite. 
The dark schist showed an excess of biotite and a few horn- 
blende shreds, with a good deal of slightly decomposed ortho- 
clase and subordinate plagioclase and qu.artz. The orthoclase 
contained a few hematite inclusions, while small crystals of 
apatite and titanite were not uncommon. Evidences of dy- 
namic action were not shown by any of the minerals in the 
section examined. 
Quite near this contact there were observed several fine 
pegmatite stringers running into the schist. A microscopic 
examination showed no strains in either the minerals of the 
stringers or the schist. The mineralogical composition at 
these points was practically the same as at the sharp contact 
just mentioned. The outline of the stringers was well marked 
even under the microscope, a very similar appearance being 
shown by a specimen in pi. I, fig. 3 of Lehmann's work.* 
The same section showed apatite grains yielding a distinct 
negative uniaxial cross. 
The absence of any marked evidences of dynamic action 
(such as crushing, wavy extinction or lines of inclusions) in 
the quarry specimens examined is to be commented on as being 
in marked contrast to the conditions occurring throughout 
the rest of the '•angen"-gneiss area, as shown later. 
The occurrence of schist as a wall-rock is local and has not 
been noticed in any of the other quarries. 
DioRiTE Dikes. 
These are found at Nos. 14 and 27 in the area. 
Dike, No. 14, appears on the cross-road between the Middle 
Patent church and the Banksville road, two miles due north 
of Banksville. 
Dike No. 27, occurs about half way down the southeastern 
slope of a steep hill on the I^ong Ridge road about 1^ miles 
northwest of Long Ridge. 
In both instances the outcrops are of limited extent. 
Dike No. l.!/. The rock is essentially a moderately fine- 
grained diorite and appears on both sides of the road. The 
general color is greenish gray, and its hornblende crystals 
*Die Entstehung der AltkryBtallinischen Schiefer. 
